Two part flywheel for a motor vehicle, the two part flywheel having a torsional vibration damper

ABSTRACT

A two part flywheel having a torsional vibration damper with a plurality of inertial masses, for installation in the drive train of a motor vehicle. The two part flywheel comprises a first inertial mass system and a second inertial mass system. The first inertial mass system comprises a plurality of planet gears. The second inertial mass system comprises a sun gear. The planet gears solely engage with the sun gear. The first inertial mass system also comprises a first planar annular wall disposed substantially perpendicular to the common axis of rotation. The second inertial mass system also comprises a second planar annular wall disposed substantially perpendicular to the common axis of rotation. At least a portion of each planet gear of said plurality of planet gears is disposed between said first annular wall and said second annular wall.

This is a division of U.S. Ser. No. 08/813,105, filed on Mar. 7, 1997,now U.S. Pat. No. 6,019,683 which claims priority from Federal Republicof Germany Patent Application No. 196 09 041.5, filed on Mar. 8, 1996.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a two part flywheel having atorsional vibration damper, in particular for installation in the drivetrain of a motor vehicle.

2. Background Information

To damp torsional vibrations in the drive train of a motor vehicle,German Utility Model 94 14 314 describes a flywheel which has twoinertial masses. A first inertial mass system is fastened to thecrankshaft of an internal combustion engine and a second inertial masssystem is mounted so that it can rotate on the first inertial masssystem and simultaneously form a friction surface of a friction clutch.The two inertial mass systems are connected to one another withrotational elasticity by means of a spring system. There is also a thirdinertial mass system which can rotate around the common axis of rotationof the two inertial mass systems. The third inertial mass system is inthe form of a planet carrier or a ring gear of a planetary gear train.The sun wheel is non-detachably connected to the first inertial masssystem and is engaged in the conventional manner with at least oneplanet wheel. The planet wheel can rotate on the common axis of rotationaxially parallel to the planet carrier. To the extent that the planetcarrier is used as the third inertial mass, the planet wheels areengaged with the ring gear which is then non-detachably fastened to thesecond inertial mass system. In embodiments in which the ring gear formsthe third inertial mass, the planet carrier of the planetary gear trainis a component of the second inertial mass system. Known flywheels whichhave a plurality of inertial masses are comparatively complex andrequire a relatively large amount of space in the axial and/or radialdirection for the installation of the components of the planetary geartrain. Additionally, the mounting of the third inertial mass isdifficult because the central area of the system of inertial masses isrequired for the installation of a number of components of the torsionalvibration damper, in particular for the installation of the bearingwhich is used to mount the second inertial mass system on the firstinertial mass system, as well as for the installation of frictiondevices, if such friction devices are present. The rotational mountingof components such as a ring gear, for example, on a relatively largediameter is also problematic.

An additional flywheel which has multiple inertial masses is describedin German Patent No. 195 17 605. On this flywheel, a first inertial masssystem is rotationally elastically coupled by means of a spring systemwith a second inertial mass system. The second inertial mass system ismounted so that it can rotate relative to the first inertial masssystem. The first inertial mass system also forms the ring gear of aplanetary gear train which is coaxial to the axis of rotation of thecrankshaft. The sun wheel of the planetary gear train is rotationallymounted on the crankshaft and is driven by means of the planet wheelswhich are engaged with the sun wheel and the ring gear. The planetwheels are also mounted on a planet carrier which is non-detachablyconnected to the engine and rotates in the direction opposite to thedirection of rotation of the crankshaft. A third inertial mass which isnon-detachably connected to the sun wheel ensures compensation forirregularities in the rotation of the crankshaft.

OBJECT OF THE INVENTION

The object of the present invention is to create a flywheel having atorsional vibration damper which has a plurality of inertial masses,which can be realized more easily and more economically than similarknown devices, and which can be kept relatively compact.

SUMMARY OF THE INVENTION

The present invention teaches that in one preferred embodiment, thisobject can be accomplished by an arrangement in which a first and secondinertial mass system are installed so that they can rotate both togetherand relative to one another around a common first axis of rotation. Thefirst and second inertial mass systems can be rotationally elasticallyconnected to one another by means of a spring system. A third inertialmass system can be movable relative to the first and second inertialmass systems. The third inertial mass system is in a rotational driveconnection with the first and/or second inertial mass systems by meansof a transmission system. One of the inertial mass systems, inparticular the first inertial mass system, is designed to be connectedto the crankshaft of an internal combustion engine.

The present invention further teaches that the inertial mass of thethird inertial mass system can be defined essentially exclusively by aplurality of inertial masses which rotate around the first axis ofrotation. Each of the inertial masses can be rotated or pivoted around acorresponding respective second axis of rotation which is offset axiallyparallel from the first axis of rotation. Each of the inertial massescan be driven in a pivoting or rotating motion around its second axis ofrotation by the transmission system as a function of the relativerotational movement between the first and second inertial mass systems.

The present invention teaches that the construction of a flywheel whichhas a plurality of inertial masses can be simplified and theinstallation space required for the flywheel which has a plurality ofinertial masses can be reduced if, instead of a third inertial masssystem which can rotate around the first axis of rotation, the inertialmass of the third inertial mass system is distributed among a pluralityof inertial mass bodies which are offset from one another in theperipheral direction. Not only can the space available be betterutilized by this distribution of the inertial masses, but the mountingof the individual inertial mass bodies can also be simplified.

The inertial mass or centrifugal mass of the inertial mass bodies isdetermined on one hand by their rotation around the second axis ofrotation, and on the other hand by the movement with which theycirculate around the first axis of rotation in the event of a relativerotation between the first and second inertial mass systems. Theinertial mass bodies must be guided for both components of movementrelative to the first and second inertial mass systems. In a firstembodiment, the present invention teaches that the inertial mass bodiesare provided over at least a portion of their periphery with toothing,gearing or gear teeth which can be concentric to the correspondingsecond axis of rotation. The inertial mass bodies are mounted on thefirst inertial mass system so that they are stationary relative to thefirst inertial mass system. The second inertial mass system comprisesmating or matching toothing, gearing or gear teeth which is concentricto the first axis of rotation and is engaged with the toothing.

The inertial mass bodies can be mounted on journals which arenon-detachably connected to the first inertial mass system. The journalsmay also form a solid unit with the corresponding inertial mass bodies.The inertial mass bodies can have teeth around their entire peripheralsurface in the manner of gear wheels. For smaller relative angles ofrotation between the first and the second inertial mass systems thetoothing can also be restricted to a portion of the periphery. In thelatter variant, the area of the inertial mass bodies which is not usedfor the toothing can be used to increase the size of the inertial mass.The mating toothing which is engaged with the toothing of the inertialmass bodies can be provided exclusively on the side of the inertial massbodies which faces radially away from the first axis of rotation orexclusively on the side which faces radially toward the first axis ofrotation. When the mating toothing is located on the side of theinertial mass bodies which faces radially away from the first axis ofrotation, a larger angular acceleration of the inertial mass bodies canbe achieved than in the other case. The relatively low rotationalacceleration of the inertial mass bodies which can be achieved by anengagement of the mating toothing on the side which faces the first axisof rotation can be advantageous if the torsional vibration dampercontains a viscous or pasty damping and/or lubrication medium, such asgrease, and the transport of grease by the teeth can be kept withinlimits.

The inertial mass, which is effective during the relative movementbetween the first and the second inertial mass systems, in the form ofthe inertial mass bodies of the third inertial mass system, can beincreased if at least one additional inertial mass system of the type ofa transmission or drive chain is in a drive connection via the inertialmass bodies with the first and second of the inertial mass systems.

In one preferred embodiment, the present invention teaches that there isa fourth inertial mass system which can rotate relative to the first andthe second inertial mass systems around the first axis of rotation. Thefourth inertial mass system is in a rotational drive connection by meansof an additional transmission system with at least one of the inertialmass bodies. Depending on the relative movement between the inertialmass bodies on the one hand and the first and second inertial masssystems on the other hand, the fourth inertial mass system can be drivenso that it rotates or pivots around the first axis of rotation. Thisconfiguration can be realized in a technically very simple manner byproviding at least the above-mentioned one inertial mass body, but inparticular each of the inertial mass bodies, on at least a portion oftheir periphery, with toothing which is concentric to the correspondingsecond axis of rotation. The fourth inertial mass system is realized inthe form of a ring-shaped inertial mass component which can rotaterelative to the first and second inertial mass systems around the firstaxis of rotation. For the formation of the second transmission system,the fourth inertial mass system can comprise a mating toothing which isconcentric to the first axis of rotation and which can be engaged withthe toothing of the inertial mass bodies. Such a ring-shaped inertialmass component can be installed without problems in the space alreadyavailable. It is appropriate if the mating toothing of the transmissionsystem and of this additional transmission system are engaged ondiametrically opposite sides, with reference to the second axis ofrotation, with the toothing of at least one of the inertial mass bodies.Depending on the arrangement of the ring-shaped inertial mass component,viewed radially, relative to the inertial mass bodies, the inertial massbodies act as step-up transmissions or as step-down transmissions. It isappropriate if the mating toothing of the ring-shaped inertial masscomponent, on the side of the inertial mass bodies next to the firstaxis of rotation, is engaged in the toothing of the inertial massbodies. While the space on the side of the inertial mass bodies fartherfrom the first axis of rotation is largely utilized by the spring systemof the torsional vibration damper, the space on the side closer to thefirst axis of rotation can thereby be better used to increase the momentof inertia.

If at least three inertial mass bodies are provided, the ring-shapedinertial mass component can be radially guided on the toothings of theinertial mass bodies. For the radial mounting of the inertial mass body,however, an annular shoulder which is non-detachably connected to one ofthe inertial mass systems, in particular the first inertial mass system,can be used. For example, the annular shoulder can be provided on aring-shaped sheet metal structural part which is non-detachablyconnected to the first inertial mass system. The ring-shaped sheet metalpart can also be used to provide a dynamic seal.

The inertial mass bodies and the ring-shaped inertial mass component canbe located radially above one another. But to make more efficient use ofthe space available, the present invention teaches that the inertialmass bodies can extend radially beyond the mating toothing of thering-shaped inertial mass component. Therefore, these components, atleast in partial areas, extend axially next to one another.

The inertial mass bodies, however, need not necessarily be mounted sothat they are stationary relative to the first or the second inertialmass system. In one variant, the present invention teaches that theinertial mass bodies are realized in the form of a rolling body and areprovided over at least a portion of their periphery with toothing whichis concentric to the corresponding second axis of rotation. The firstinertial mass system comprises a guide track which is concentric to thefirst axis of rotation for the inertial mass bodies. The second inertialmass system has a mating toothing which is concentric to the first axisof rotation and is engaged with the toothing of the inertial massbodies. The guide track and the mating toothing guide the inertial massbodies radially. The guide track can be a smooth-surfaced, e.g.cylindrical, peripheral surface, or can have an additional matingtoothing, with which the toothing of the inertial mass bodies mayengage. There is no need for separate journals and bearingscorresponding to the inertial mass bodies. When the guide track isrealized in the form of a smooth, e.g. cylindrical, rolling surface, itis sufficient to provide a single mating toothing on the second inertialmass system. If there is a non-toothed guide track, smooth rollingsurfaces can also be appropriately provided on the inertial bodies.

The inertial mass bodies are appropriately shaped so that theinstallation space available in the torsional vibration damper isoptimally utilized to increase the moment of inertia of the inertialmass bodies. The toothing of the inertial mass bodies preferably doesnot extend over the entire axial width, so that it also becomes possibleto utilize the installation space between the teeth of the toothing toincrease the inertial masses. The inertial mass bodies preferably havean area which projects radially outward and/or axially beyond thetoothing. In embodiments in which the spring system and the inertialmass bodies are located in a chamber which contains a viscous medium,axially closed toothings can facilitate the dynamic sealing of thechamber, because with axially closed toothing, the transport oflubricant caused by the toothing can be reduced. Such an arrangement canbe advantageous if dynamic seals are placed in the vicinity of the axialsurfaces of the inertial mass bodies.

One embodiment which is particularly easy to manufacture and ismechanically rugged in operation is characterized by the fact that thefirst or the second inertial mass system, in particular the firstinertial mass system, has a first sheet metal structural part. The firstsheet metal structural part can have a first planar annular wall whichruns essentially radially in relation to the first axis of rotation, andan at least approximately ring-shaped chamber which essentiallyencircles or surrounds the first axis of rotation concentrically. The atleast approximately ring-shaped chamber is used for the installation ofat least one spring of the spring system. The spring is connected to thefirst sheet metal structural part. The other of these two inertial masssystems has a second sheet metal structural part coupled in the chamberwith the spring. The second sheet metal structural part, with a secondplanar annular wall which runs essentially radially in relation to thefirst axis of rotation, is opposite and at some distance from the firstannular wall. The inertial mass bodies are located axially between theradially-running annular walls of the sheet metal structural parts. Thechamber surrounds all the inertial mass bodies on the radial outside.Such a torsional vibration damper is relatively flat in the axialdirection. In particular, the two annular walls can be utilized asapproach surfaces to fix the inertial mass bodies in position, whichsimplifies the assembly and installation operations. It is sufficient ifthe annular walls run only partly perpendicular to the axis and areflat, for example in a ring-shaped area which radially overlaps theinertial mass bodies. It is preferable if the annular wall of at leastone of the two sheet metal structural parts is perpendicular to the axisof rotation and is planar or flat in relation to the axis of rotationover the entire radial height of the inertial mass bodies, to ensure asafe and reliable guidance of the inertial mass bodies as they rotateand pivot.

As indicated above, the chamber designed for the installation of thespring system can be filled at least partly with a viscous medium. Forthis purpose, the chamber is realized so that it is tight or sealed onthe radial outside, to prevent the discharge or loss of the medium bycentrifugal motion, and to prevent the ejection of grease spatters evenwhen the torsional vibration damper is stationary. The chamber is sealedtoward the radial inside by additional dynamic seals. Normally, lessstringent requirements are set for the quality of the seal which must beprovided by these dynamic seals. To facilitate the creation of the sealthe areas of the ring walls formed by the sheet metal structural partswhich are radially next to the chamber are axially close to the axialend surfaces of the inertial mass bodies. This configuration isadvantageous if the mating toothing on the side which faces the chamberis engaged with the toothing of the inertial mass bodies, and theviscous medium is under the displacement pressure of teeth which areengaged with one another.

To reduce the pressure with which the toothings engaged with one anotherdisplace the viscous medium, which can be grease or a similar substance,in the area near the toothing there can be an annular pocket which isopen on the side toward the toothing. The annular pocket can be used tohold the medium at least temporarily. This annular pocket can be createdby means of a very simple construction, if the annular wall of the sheetmetal structural part which comprises the mating toothing makes atransition, forming an annular pocket which is radially open, into anannular area of the sheet metal structural part which contains themating toothing. In terms of manufacturing technology, it is therebyvery simple to obtain an embodiment in which the annular area isrealized in the form of a ring-shaped disc provided with the matingtoothing, and is fastened to a disc part of the sheet metal structuralpart, in particular by welding.

In other words, the annular area can be realized in the shape of a ringshaped disc. The annular area may be located between the mating toothingand the annular wall of the sheet metal structural part. The annulararea can be formed by preferably angling the annular wall towards themating toothing and welding the end of the annular wall to the matingtoothing.

In one preferred embodiment, the second sheet metal structural part, onthe side of the second annular wall which faces the first axis ofrotation, forms an annular web which leads axially away from the firstsheet metal structural part. The annular web connects the second annularwall with a hub area of the second sheet metal structural part, whichhub area acts as a pivot bearing. The hub area supports a ring-shapedflywheel which is located at some distance from the second annular wall.The flywheel is appropriately a mating application plate of the frictionclutch which is downstream of the torsional vibration damper in thedrive train of the motor vehicle. Axially between the second annularwall and the flywheel there is a radially extending third annular wallof the first sheet metal structural part. The third annular walldefines, limits or closes the chamber radially toward the flywheel. Thisembodiment is characterized by sheet metal structural parts which arevery simple to manufacture. The structure is nevertheless mechanicallystable in operation, and the sealing of the chamber which surrounds theinertial mass bodies in the manner of a ring is a simple matter. A basicsealing of the chamber can be achieved in a simple manner by overlappingthe third annular wall with the second annular wall, at least in aportion of its area, with essentially parallel surfaces. The overlappingcan cover a wide area without any problems. In particular, it is easy tomake the ring-shaped gap which remains between the second and the thirdannular wall very narrow, and if necessary, the two annular walls canalso come into contact with one another. Any friction that may be causedby the contact can be utilized for the generation of the basic frictionof the torsional vibration damper. The radial length of the annular gapcan easily be made relatively large. In particular, the third annularwall can essentially extend to the annular web.

In one preferred embodiment, the second and the third annular walls, inthe vicinity of the inside periphery of the third annular wall, form anannular gap which becomes wider radially inward, and, in spite of thenarrow dimension of the area of the annular gap, captures the viscousmedium being discharged and returns it by centrifugal force into thechamber. The widening of the annular gap also results in a change inpressure and thus an interruption of any radially inward grease flow.The annular gap can be created by an essentially cone-shaped bending ofthe inside periphery of the third annular wall. An encircling beadworked into the third wall is also suitable, if the bead is curved awayfrom the second annular wall so that on its side facing the first axisof rotation it extends back to the second sheet metal structural part.The inside periphery of the third annular wall, which inside peripheryis next to the first axis of rotation, can form, with the second sheetmetal structural part, a dynamic seal in the area between the bead andthe first axis of rotation.

The flywheel is appropriately held firmly connected to the hub areawhich is held by the annular web at an axial distance from the secondannular wall. In this manner, between the second annular wall and theflywheel there is an annular gap which extends essentially in the radialdirection. The annular gap preferably contains not only the thirdannular wall of the first sheet metal structural part, but can also beused for the ventilation and cooling of the construction. The annulargap can be used for ventilation and cooling if, in the vicinity of theinside periphery of the flywheel or of a neighboring part of theconstruction, there are a plurality of openings which are offset in theperipheral direction and the annular gap between the flywheel and thethird annular wall is open toward the radial outside. The openings canbe realized in the form of axial holes in the flywheel or in the form ofradial channels between the hub area of the second sheet metalstructural part and the flywheel. In a version which is particularlyfavorable from a manufacturing point of view, the openings are providedin the hub area of the second sheet metal structural part radiallybetween the annular web and the flywheel, because openings can belocated at this point particularly easily. In particular, themanufacture of the openings does not require any special castingmeasures for the configuration of the openings in the flywheel, which isconventionally realized in the form of a cast structural part. Theventilation action can be increased even further if the third annularwall extends with its inside periphery radially into the area betweenthe annular web and the openings, and in the area of its insideperiphery is bent axially away from the second annular wall. Thisbending causes a deflection of the cooling air transported radiallyoutward between the third annular wall and the flywheel and can alsoform the above-mentioned radial gap between the second and the thirdannular wall, which radial gap becomes wider toward the radial insideand improves the seal.

The annular web can be realized in one piece with the second annularwall and/or the hub area of the second sheet metal structural part.These components, however, can also be composed of a plurality of sheetmetal parts which are manufactured separately from one another and arethen non-detachably connected to one another, in particular by welding.In one preferred embodiment, the present invention teaches that theannular web is realized in the form of a sleeve which, on the side ofthe inertial mass bodies next to the first axis of rotation, axiallyoverlaps the toothing of the inertial mass bodies and carries the matingtoothing. The mating toothing can be created by cutting andmetal-removing machining methods. However, the mating toothing can alsobe formed by stamping. In this context, embodiments of the sleeve inwhich the sleeve extends to the first sheet metal structural part arealso advantageous, as well as embodiments in which the sleeve forms adynamic seal, e.g. a gap seal or diaphragm seal, with the first sheetmetal structural part, possibly also forming a contacting seal usinggaskets.

To improve the sealing of the chambers, additional contacting seals canbe provided. As mentioned above, between the third annular wall and thesecond sheet metal structural part, for example, it is possible toprovide not only gap seals, but also contacting dynamic seals, inparticular on the radially inner edge of the third annular wall.Additional dynamic seals can be provided radially between the first axisof rotation and the inertial mass bodies between the first and thesecond sheet metal structural parts. The additional dynamic seals in theform of axial sealing sleeves or bushings are preferably fastened to oneof the sheet metal structural parts and extend to an axially runningannular wall of the other sheet metal structural part, to which they arevery close or with which they are even in contact.

In other words, additional dynamic seals or sheet metal sealing partscan be placed on the radial inside of the inertial mass bodies. Thesheet metal sealing part is preferably placed between the first andsecond sheet metal structural parts. The sheet metal sealing part canextend from one of the sheet metal structural parts to the annular wallof the other sheet metal structural part. The one end of the sheet metalsealing part can come close to or even contact the annular wall. Thesheet metal sealing part can have ends that are substantially parallelwith the first and second sheet metal structural part.

The sheet metal sealing parts provided to create a dynamic seal can bewelded or riveted to the components or sheet metal structural parts ofthe first or of the second inertial mass systems. It is also appropriateto bolt this sheet metal seal part on the crankshaft, together with thefirst or the second inertial mass systems, by means of the same screws.

The configuration of the sheet metal structural parts and the system ofinertial mass bodies explained above makes it possible to createfriction devices in a simple manner. For example, the second sheet metalstructural part and the third annular wall can be supported frictionallyon one another, at least in a portion of their areas. Depending on themagnitude of the axial application force and the friction pair, thisfriction point can be used to generate a portion of the basic frictionand/or the load friction. Friction devices for the basic friction or theload friction can also be created by biasing the inertial mass bodieswhich are located axially between essentially radially running annularwalls of the first and second inertial mass systems, by means of atleast one axially acting spring, for example at least one plate springin frictional contact with at least one of these annular walls. Incontrast to known friction devices, the inertial mass bodies whichrotate or pivot axially parallel to and at an offset from the first axisof rotation can also be used to generate friction forces. The number andthe configuration of the exposed friction surfaces in this area make itpossible to more effectively adapt the friction devices to the specificinstallation conditions.

If the inertial mass bodies are rotationally mounted by means ofjournals on the first sheet metal structural part, as explained above,the mounting can be cantilevered or overhung, i.e. by means of journalswhich are held axially only on one side on the first sheet metalstructural part. The journals can be separately manufactured componentswhich are fastened to the first sheet metal structural part, butpreferably they are formed as integral parts of the first sheet metalstructural part and are stamped or pressed out of the material of thefirst sheet metal structural part.

The simple configuration of the two sheet metal structural parts, whichform the first and the second inertial mass systems, makes it possibleto form hub areas on these sheet metal structural parts, or to attachthem non-detachably, e.g. by welding, as a result of which the twoinertial mass systems are rotationally mounted and guided radially andpossibly also axially, so that they can rotate relative to one another.For example, the two sheet metal structural parts can have bearing lugs,necks or carriers which are formed in one piece with them and areengaged coaxially with one another, by means of which they are mountedon one another. In one particularly simple embodiment, which also makespossible a simple installation, the bearing lugs project axially towardone another from the sheet metal structural parts. The bearing lug ofone of the sheet metal structural parts can be provided directly withfastening means, such as holes for fastening screws, for the attachmentto the crankshaft of the internal combustion engine, and with itsbearing lug encloses the bearing lug of the other sheet metal structuralpart, preferably from the radial outside. This configuration has theadvantage that the distance between the flywheel, which is subjected toa thermal load by the friction clutch, and the bearing located betweenthe bearing lugs, such as a ball bearing, can be sized relatively large,which reduces the thermal load on the bearing.

The bearing can be a ball bearing or a similar bearing. Plain orfriction bearings are also suitable, in particular plain bearings with abearing ring made of plastic which is capable of withstanding hightemperatures between the bearing lugs of the sheet metal structuralparts. The bearing ring can have an L-shaped cross section, and canextend around the edge of the radially outer bearing lug to absorb axialforces.

The above discussed embodiments of the present invention will bedescribed further hereinbelow with reference to the accompanyingfigures. When the word “invention” is used in this specification, theword “invention” includes “inventions”, that is, the plural of“invention”. By stating “invention”, the Applicant does not in any wayadmit that the present application does not include more than onepatentably and non-obviously distinct invention, and maintains that thisapplication may include more than one patentably and non-obviouslydistinct invention. The Applicant hereby asserts that the disclosure ofthis application may include more than one invention, and, in the eventthat there is more than one invention, that these inventions may bepatentable and non-obvious one with respect to the other.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is explained in greater detail below, withreference to the embodiments illustrated in the accompanying drawings,wherein:

FIG. 1 shows a partial axial cross section through a flywheel which hasa plurality of inertial masses, with a torsional vibration damperlocated in the drive train of a motor vehicle, viewed along a line I—Iin FIG. 2;

FIG. 2 shows a partial axial longitudinal section through the flywheelwith a plurality of inertial masses, viewed along a line II—II in FIG.1;

FIGS. 3 to 6 show partial longitudinal sections through variants of theflywheel with multiple inertial masses illustrated in FIG. 2; and

FIG. 6a illustrates additional Features of the flywheel depicted in FIG.6.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 and 2 show detailed illustrations of portions of one-half of aflywheel which has a plurality of inertial masses and is located in thedrive train of a motor vehicle. The multiple-mass flywheel can includean inertial mass system 3 which can be fastened concentrically with anaxis of rotation 1 on a crankshaft of an internal combustion engine of amotor vehicle. A second inertial mass system 7 can be rotationallymounted equiaxially with the axis of rotation 1, on the inertial masssystem 3, by means of a bearing 5, in particular a ball bearing. Theinertial mass system 7 can form the carrier for a friction clutch of thedrive train and may be connected rotationally elastically to the firstinertial mass system 3 by means of a damping spring system 9. Thedamping spring system 9 can act directly between the two inertial masssystems 3, 7.

The first inertial mass system 3 may include, as the carrier ofadditional components of the flywheel which has a plurality of inertialmasses, a sheet metal structural part 11. The sheet metal structuralpart 11 can have an annular wall 13 which extends essentially radiallyin relation to the axis of rotation 1 and is flat, at least in portions.The annular wall 13, on its inside periphery, can support a tubularbearing lug 15 which may project axially and is preferably formed in onepiece with the ring wall or annular wall 13. The bearing lug 15 canguide the bearing 5 radially on its outside periphery. The annular wall13, in the vicinity of the bearing lug 15, can be provided with aplurality of holes 17. The holes 17 may be distributed in the peripheraldirection for fastening screws which are not illustrated in any furtherdetail, and the means by which the inertial mass system 3 can be screwedonto a crankshaft which is also not shown, but which would be located onthe left in FIG. 2.

The inertial mass system 7 can include a sheet metal structural part 19which may be in the form of an approximately ring-shaped disc and can beradially engaged with the bearing 5 in a hub area 21. The sheet metalstructural part 19 can include a bearing lug 23 which projects axiallyin the direction opposite to the bearing lug 15. The bearing lug 23 canoverlap coaxially with the bearing lug 15, and by means of which thesheet metal structural part 19 is radially guided on the insideperiphery of the bearing 5. The bearing lugs 15, 23 can also fix thesheet metal structural parts 11, 19 at least axially in relation to oneanother. By means of a plurality of rivets 25 distributed in theperipheral direction, a ring-shaped flywheel 27, e.g. made of castmaterial, may be fastened at a radial distance from the bearing lug 23on the sheet metal structural part 19. A flat side 29 of the flywheel 27farther from the crankshaft can also form a friction surface of thefriction clutch which is not illustrated in any further detail. Thefriction clutch can be fastened to the flywheel 27 in the conventionalmanner.

In the vicinity of the outside periphery of the sheet metal structuralpart 11, a cylindrical peripheral wall 31 can be formed in one piecewith the sheet metal structural part 11. The cylindrical peripheral wall31 can extend axially, to increase the moment of inertia of the inertialmass system 3. The cylindrical peripheral wall 31 can have an extension33 which, in one embodiment, may extend axially beyond the flywheel 27.The cylindrical peripheral wall 31 may also carry a non-rotationalring-shaped starter motor ring gear 35. Adjacent to the essentiallyplanar ring wall 13 of the sheet metal structural part 11, radiallyoutwardly, can be a wall area 37, from the outside periphery of whichthe peripheral wall 31 may project and which, together with theperipheral wall 31 and a top or cover wall 39 which can essentially bein the shape of a ring-shaped disc and can extend at some distance fromthe wall area 37, can define an approximately ring-shaped chamber 41which may surround or enclose the axis of rotation 1.

In other words and in accord with one possible embodiment of the presentinvention, the wall area 37 can be disposed radially inward of theperipheral wall 31 and adjacent to the annular wall 13. The top wall 39can be disposed radially inward of the peripheral wall 31 andsubstantially parallel to the wall area 37. The wall area 37, theperipheral wall 31 and the top wall 39 may define three sides of anapproximately ring-shaped chamber 41. The ring-shaped chamber 41 ispreferably disposed about the axis of rotation 1.

The chamber 41 is preferably sealed tight on the radial outside. The topwall 39 is preferably non-detachably connected in a sealed manner in thevicinity of its outside periphery by a weld seam 43. The top wall 39 canbe connected with the sheet metal structural part 11 to form a singleunit. Projecting into the chamber 41 can be a plurality of extensions orarms 45 which are offset from one another in the peripheral direction.The arms 45 can project radially outward from a ring 47 which isnon-detachably connected, e.g. by welding, to the sheet metal structuralpart 19. Control plates 49 which may have contours which match the arms45 can be located axially on both sides of each arm 45. The controlplates 49 can be non-detachably connected with the walls which form thechamber 41, e.g. the wall area 37 and the top wall 39. Between arms 45or control plates 49 which may be next to one another in the peripheraldirection, as shown most clearly in FIG. 1, in the channel 41 there canbe a plurality of coil compression springs 51 arranged in a row onebehind another. Between neighboring coil compression springs 51, slidingblocks 53 may be engaged. The sliding blocks 53 are guided so that theycan slide along the inside periphery of the peripheral wall 31. The coilcompression springs 51 which are next to the arms 45 may be supported bymeans of spring shoes 55 on the arms 45 and the control plates 49. Thecoil compression springs 51 can, although they do not have to, beinstalled with bias between the arms 45 or control plates 49 which arenext to one another in the peripheral direction. When there is arelative rotation of the inertial mass system 7 relative to the inertialmass system 3 around the axis of rotation 1, the coil compressionsprings 51, which are shown in their rest position in FIG. 1, can eachbe compressed between an arm 45 and the pair of control plates 49following it in the peripheral direction. As a result of which the twoperipheral mass systems 3,7 can be coupled to one another withrotational elasticity, as is the case in conventional two-mass flywheelsin the drive train of a motor vehicle. The torque may thereby betransmitted directly between the sheet metal structural parts 11 and 19.

The inertial mass and the moment of inertia of the first inertial masssystem 3 can essentially be defined by the sheet metal structural part11, the top wall 39, the control plates 49 and the starter rim 35, aswell as by some of the coil compression springs 51. The moment ofinertia of the second inertial mass system 7 may essentially be definedby the flywheel 27, the sheet metal structural part 19, the ring 47 andthe arms 45, as well as by some of the coil compression springs 51, ifsuch springs are present. The inertial masses of the two inertial masssystems 3, 7 together with the damping spring system 9, form amechanically oscillating system which can make it possible, in a knownmanner, to filter excitations in the drive train of motor vehicles, orto shift characteristic frequencies into speed ranges in which they donot have any undesirable effects. Because the space which can be usedfor the installation of the inertial masses is a function both of thesize and the shape of the space available in the vehicle, it mayfrequently be difficult to provide suitable configurations which meetboth the space and performance requirements, as well as the requirementsset for the oscillating or inertial system.

The torsional vibration damper illustrated in FIGS. 1 and 2, in additionto the inertial masses of the inertial mass systems 3 and 7 which canrotate relative to one another around the axis of rotation 1, maycomprise a third inertial mass system which is in the form of aplurality of inertial mass bodies 57 distributed in the peripheraldirection. The inertial mass bodies 57 are preferably rotationally orpivotably mounted on journals 59 which can be held firmly in the annularwall 13 of the sheet metal structural part 11 by means of bearings 61,such as ball bearings, needle bearings, or simply coated journals.

In other words, and in accord with one possible embodiment of thepresent invention, the torsional vibration damper may comprise a thirdinertial mass system. The third inertial mass system preferablycomprises a plurality of inertial mass bodies. The inertial mass bodies57 can be rotationally mounted on journals 59 by bearings 61. Thejournals 59 can be attached to the annular wall 13 of the sheet metalstructural part 11.

The inertial mass bodies 57 can be provided on a peripheral area withtoothing 65 which is preferably formed in one piece on a ring 47 andwhich, together with a mating toothing 67, jointly surrounds theinertial mass bodies 57 on the side farther from the axis of rotation 1.

In other words and in accord with one possible embodiment of the presentinvention the inertial mass bodies 57 can have a peripheral area whichmay include toothing 65. The ring 47 can include mating toothing 67which can mesh with the toothing 65 of the inertial mass bodies 57. Themeshing of the toothing 65 and the mating toothing 67 preferably occursat the radially outer side of the inertial mass bodies 57.

In the event of a relative rotation of the inertial mass systems 3, 7,the inertial mass bodies 57 are driven in rotation around the axis ofrotation 63 by the toothings 65, 67 which form a transmission. Theinertial mass of the inertial mass bodies 57 can thereby influence theoscillation or inertial behavior of the inertial mass systems 3, 7 whichmay be coupled to one another with rotational elasticity by means of thespring system 9, utilizing the space available between the sheet metalstructural parts 11, 19. Because the inertial mass bodies 57 representthe only inertial masses which are driven by the toothings 65, 67, arelatively large mass with the simplest possible construction can becreated, which makes it possible to vary the oscillation or inertialcharacteristics within a wide range.

In the illustrated embodiment of FIGS. 1 and 2, the toothing 65 canextend over essentially the entire peripheral surface of each inertialmass body 57, to take into consideration even large relative angles ofrotation between the inertial mass systems 3, 7. The axial width of thetoothing 65, however, can correspond essentially only to the axial widthof the mating toothing 67. To increase the inertial mass, the toothing65 is preferably closed on the flat side next to the sheet metalstructural part 11, and as shown at 69, the area of the material of theinertial mass body 57 projects both axially and radially beyond thecontour of the toothing 65. The inertial mass bodies 57 also have endsurfaces which are preferably perpendicular to the axis of rotation 1.The inertial mass bodies 57 can be axially fixed in position between theannular wall area 13 of the sheet metal structural part 11, whichannular wall area 13 extends radially over the entire diameter of theinertial mass body 57, on the one hand, and an annular wall area 71 ofthe sheet metal structural part 19, which annular wall area 71 mayextend in a plane perpendicular to the axis of rotation 1. The annularwall 71 of the sheet metal structural part 19, in the vicinity of thejournal 59, can make a transition into an annular web 73 in the hub area21. The annular wall 71 of the sheet metal structural part 19 ispreferably bent downward on its outside periphery at an angle 75 towardthe ring 47, where it can be welded along a weld seam 77 whichpreferably runs radially outside the mating toothing 67.

The chamber 41 can be filled at least partly, but at least up to thevicinity of the coil compression springs 51, with a viscous medium suchas grease. The grease which, in addition to its lubrication action,performs a certain damping action on account of the components which canmove relative to one another in the chamber 41. The amount of greaseused can be the amount which is sufficient for the lubrication of thetoothings 65, 67, but it can also extend at least partly to the insideperiphery of the ring 47.

In another possible embodiment of the present invention the amount ofgrease used may be sufficient to lubricate the toothings 65, 67 and toallow some of the grease to escape to a space that may be disposed nextto the ring 47. Further, the amount of grease used may be sufficient tolubricate the toothings 65, 67 and to partially fill the chamber 41.

The chamber 41, toward the radial outside, is preferably sealed so thatit remains tight even under the pressure of the grease caused bycentrifugal force. Toward the radial inside, the quality requirementsset for the seal of the chamber 41 can be significantly less stringent,and in the extreme case, on account of the consistency of the grease, itmay be possible to dispense with the seal altogether. In the illustratedembodiment of FIGS. 1 and 2, the seal of the bearing 5, which may berequired in any case, seals the area between the sheet metal structuralparts 11, 19 on the radial inside. The inertial mass bodies 57 which canbe in contact by means of their flat end surfaces against the planarannular walls 13, 17, can define the cross section for the passage ofthe grease from the chamber 41 to the bearing 5 and prevent the rollingmovement of the toothings 65, 67 from transporting grease directly fromthe chamber 41 into the vicinity of the bearing 5. In particular, thematerial areas 69 which close or enclose the toothing 65 axially canprevent the rolling movement from pressing grease out of the toothingsdirectly into the space between the annular wall 13 and the inertialmass bodies 57. Between the annular wall 71 and the inertial mass bodies57, next to the engagement area of the toothings 65, 67, there ispreferably an annular space 79 which can also hold the grease which hasbeen squeezed out of the toothing. Otherwise, the chamber 41, on theside of the flywheel 27, is preferably sealed relative to the sheetmetal structural part 19 by the top wall 39. The top wall 39 can projectinto an annular space 81 defined between the ring wall 71 and theflywheel 27 by the annular web 73. The top wall 39 may overlap with thecutside of the planar annular wall 71, forming a gap seal essentiallyover the entire radial height of the annular wall 71. The top wall 39can also form a contacting seal with the annular wall 71. The moment offriction of the contacting seal can also be used, if necessary, togenerate a basic friction of the torsional vibration damper.

The following description relates to variants of the flywheel which hasa plurality of inertial masses as described in FIGS. 1 and 2. Componentswhich correspond to those described above in terms of their constructionand function are identified by the same reference numbers as in FIGS. 1and 2, but they are also provided with a letter for more specificidentification. Reference is hereby made to the entire precedingdescription for components not specifically discussed herebelow.

The flywheel which has a plurality of inertial masses and is illustratedin FIG. 3 differs from the embodiment illustrated in FIGS. 1 and 2essentially in that between the end surface of each of the inertial massbodies 57 a and at least one of the axially neighboring annular walls 13a and 71 a, in this case the annular wall 71 a of the sheet metalstructural part 19 a, an axially acting spring 85, in this case a platespring, is clamped. The plate spring 85 can compensate for any axialplay of the inertial mass body 57 a which may be present. The platespring 85 may cause a frictional damping between the inertial mass body57 a and at least one of the sheet metal structural parts 11 a, 19 a.The friction device thereby created can be sized or designed for thebasic friction of the torsional vibration damper, although it can alsobe sized for the load damping. The friction pair need not be defineddirectly between the materials of the inertial mass bodies 57 a on theone hand and the sheet metal structural parts 11 a, 19 a on the otherhand. If necessary, additional friction rings and thrust collars orsimilar devices (not shown) can also be located between thesecomponents.

In the embodiment illustrated in FIGS. 1 and 2, the seal of the twosheet metal structural parts 11, 19 can be created by the seal of thebearing 5, which seal is not shown in any additional detail. In theembodiment illustrated in FIG. 3, on the other hand, in addition to, oras an alternative to the seal of the bearing 5 a, there can also be asleeve-shaped sealing plate 87 which is preferably held by means of therivet 25 a in the sheet metal structural part 19 a. The sleeve-shapedsealing plate 87 can extend axially on the side of the inertial massbodies 57 a facing the axis of rotation 1 a between the sheet metalstructural parts 11 a and 19 a. The sleeve-shaped sealing plate 87 canform a gap seal with the sheet metal structural part 11 a, but it canalso be used to form a dynamic seal.

In the embodiments illustrated in FIGS. 1 to 3, the mating toothing 67,67 a which can be engaged with the toothings 65, 65 a on the inertialmass bodies 57, 57 a can also be located on the side of the inertialmass bodies 57, 57 a which preferably faces radially away from the axisof rotation 1, 1 a. This configuration results in a relatively largeangular acceleration of the inertial mass bodies 57, 57 a as well as arelatively large angle of rotation of the inertial mass bodies 57, 57 a.In the embodiment illustrated in FIG. 4, the mating toothing 67 b whichcan be engaged with the toothings 65 b of the inertial mass bodies 57 bis preferably located on the annular web 73 b facing the side of theinertial mass bodies 57 b which faces the axis of rotation 1 b to reducethe angular acceleration of the inertial mass bodies 57 b and themaximum angle of rotation of the inertial mass bodies 57 b. In theillustrated embodiment of FIG. 4, an annular web 73 b which can connectthe annular wall 71 b and which can extend perpendicular to the axis ofrotation 1 b with the hub area 21 b of the sheet metal structural part19 b is preferably realized in the form of a sleeve, bush or bushing.The annular web 73 b can be concentric to the axis of rotation 1 b andcan be provided with the mating toothing 67 b. The annular web or sleeve73 b can be a sheet metal part in which the mating toothing 67 b isformed. The mating toothing 67 b can also be realized in the form of atoothed ring or gear ring which is manufactured separately.

In at least one embodiment of the present invention shown in FIG. 4, theinertial mass bodies 57 b are essentially planet gears 57 b. Each of theplanet gears 57 b is substantially gear-shaped with a toothing 65 bdisposed on the cylindrical edge or periphery of each planet gear 57 b.The annular web 73 b, which is disposed substantially concentric to thecommon axis of the two mass flywheel, is substantially ring-shaped andforms a sun gear 73 b. The sun gear 73 b is also gear-shaped with atoothing 67 b disposed on the cylindrical edge or periphery of the sungear 73 b. The toothing 65 b of each of the planet gears 57 b isconfigured to engage solely with the toothing 67 b of the sun gear.

The structural part 11 b comprises a plurality of holes 17 b and a firsthub area 317 which faces opposite the second hub area 21 b of thestructural part 19 b, as shown in FIG. 4. The bearing lug 15 b extendsin the axial direction from the first hub area 317.

FIG. 4 further shows the approximate radial distance at which differentcomponents are located with respect to the common axis of the two massflywheel. The first bearing lug 15 b is located a first distance fromthe common axis, while the second bearing lug 23 b is located a seconddistance from the common axis, whereby the first distance is greaterthan the second distance, as shown in FIG. 4. The chamber 41 b islocated at a third distance from the common axis, while the planet gears57 b are located at a fourth distance from the common axis, whereby thethird distance is greater than the fourth distance, as shown in FIG. 4.The toothing 67 b of the sun gear 73 b is located at a fifth distancefrom the common axis, whereby the fourth distance, which is the distanceof the planet gears 57 b from the common axis, is greater than the fifthdistance.

The sleeve 73 b can be welded at 89 to the hub area 21 b of the sheetmetal structural part 19 b. The sleeve 73 b can extend to form a gapseal 91, to close to the sheet metal structural part 11 b. Instead ofthe gap seal 91 a contacting dynamic seal can also be provided. Thebearing 5 b is once again sealed.

In contrast to the embodiment illustrated in FIGS. 1 to 3, FIG. 4illustrates that the arms 45 b can be formed in one piece with the bentportion 75 b. The bent portion 75 b is preferably adjacent to theradially outer area of the annular wall 71 b.

The top wall 39 b, in the vicinity of its inside periphery, can beprovided with a ring-shaped bent portion 93, which in the area betweenthe annular wall 71 b and the top wall 39 b can form an annular gap 95.The annular gap 95 may expand conically toward the radial inside. Theannular gap 95 can be adjacent to the sealing gap which may be leftbetween the annular wall 71 b and the top wall 39 b. The annular gap 95can relieve the pressure on the grease which, under certaincircumstances, is discharged from this gap, and thus improve the sealingaction.

The rivets 25 b can be located on the side of the sleeve-shaped annularweb 73 b which is farther from the axis of rotation 1 b. Radiallybetween the flywheel 27 b and the area of the annular web 73 b there canbe a plurality of openings 97 of sheet metal structural part 19 b whichopenings 97 can be distributed in the peripheral direction. The openings97 make it possible for cooling air to flow radially outward through theannular gap 81 b. The annular gap 81 b is open on the radial outside tocool the flywheel 27 b and the damping spring system 9 b. The top wall39 b, with its bent portion 93, can extend radially beyond the openings97 and simultaneously can ensure a deflection of the cooling air currentwhich enters the axial openings 97 to the radial annular gap 81 b.

The inertial mass bodies 57 b can be provided with increased mass, asindicated at 69 in FIG. 2. There can also be friction devices, such asthose explained in connection with the spring 85 with reference to theembodiment illustrated in FIG. 3.

In the embodiments explained above, the inertial mass bodies 57, 57 a,57 b are preferably fixed in position in a stationary but rotationalmanner on the crankshaft-side sheet metal structural part 11, 11 a, 11 bby means of journals or similar devices 63, 63 a, 63 b. In theembodiment illustrated in FIG. 5, the inertial mass bodies 57 c arepreferably in the form of roller bodies. The inertial mass bodies 57 ccan circulate around the axis of rotation 1 c without a stationarypositioning of their axis of rotation 63 c relative to the two sheetmetal structural parts 11 c, 19 c. Each inertial mass body 57 c canrotate around their respective axes of rotation 63 c. The inertial massbodies 57 c can be guided radially between the mating toothing 67 cprovided on the ring 47 c of the sheet metal structural part 19 c andengaged with the radially outer areas of the toothings 65 c on one hand,and an additional mating toothing 99 on the other hand. The additionalmating toothing 99 can be provided on a gearing carrier 101. The gearingcarrier 101 can concentrically surround the axis of rotation 1 c and, inoperation, can be non-detachably connected to the sheet metal structuralpart 11 c. To axially fix the inertial mass bodies 57 c in position,there can be axially acting springs 85 c, for example plate springs. Theplate springs 85 c can also be used to generate a friction moment, aswas explained above with reference to FIG. 3. One or, if necessary,both, springs 85 c can also be omitted.

One of the two mating toothings 67 c or 99 can be omitted if a guidetrack is formed in one piece on the ring 47 c or on the carrier 101. Theinertial mass bodies 57 c can roll over said guide track whilemaintaining a uniform distance from the axis of rotation 1 c.

Another difference illustrated in FIG. 5 from the embodiment illustratedin FIG. 4 is the configuration of the top wall 39 c. The top wall 39 con its radially outer end can be provided with a bent portion 103. Thebent portion 103 can follow the extension 33 c of the first sheet metalstructural part 11 c, to increase the moment of inertia of the firstinertial mass system 3 c. The weld seam 43 c can encircle, connect andseal the end surfaces of the extension 33 c and the bent portion 103. Inthe radially inner area, the top wall 39 c can be provided with a bead93 c which encircles the axis of rotation 1 c in the manner of a ring.The bead 93 c can project in a curved manner toward the hub area 21 c ofthe sheet metal structural part 19 c. Together with the annular wall 71c, the radially outer wall area of the bead 93 c forms a wedge-shapedannular gap 95 c which becomes wider radially inward.

In another possible embodiment of the present invention, the bead 93 cand the annular wall 71 c can form a wedge-shaped annular gap 95 c. Theannular gap 95 c can become axially wider in the portion of the curve ofthe bead 93 c closest to the hub area 21 c.

As explained with reference to FIG. 4 for the bent portion 93, thepurpose of this configuration in FIG. 5 is to improve the seal of anyannular gap which may remain between the annular wall 71 c and the topwall 39 c. Another purpose of the configuration in FIG. 5 can be tofacilitate a deflection of the cooling air stream which enters throughopenings 97 c of the hub area 21 c toward the annular gap 81 c. In theradially outer area, the flywheel 27 c can have a thicker portion 105with radial grooves 107 designed to transport cooling air. The thickerportion 105 can project toward the top wall 39 c to increase theinertial mass of the flywheel 27 c.

At 109, the radially inner edge of the top wall 39 c forms a dynamicseal with the sheet metal structural part 19 c in the vicinity of theannular web 73 c. In the vicinity of the annular web 73 c, an additionalsealing sleeve 87 c which is elastic in the radial direction can ensurea dynamic seal toward the gearing carrier 101.

In the embodiments illustrated in FIGS. 1 to 4, the bearing 5, 5 a, 5 bwhich guides the two inertial masses rotationally in relation to oneanother is realized in the form of a roller bearing, in particular anaxially sealed roller bearing. In the embodiment illustrated in FIG. 5,the bearing 5 c can be realized in the form of a plain bearing and cancomprise a bearing ring 111, which bearing ring 111 has an L-shapedcross section. The bearing ring 111 can guide the two sheet metalstructural parts 11 c and 19 c radially in relation to one another andfix the two sheet metal structural parts 11 c and 19 c axially inposition in relation to one another. The plastic used can include aconventional, e.g. sintered, bearing material. Coatings which havefavorable temperature and frictional characteristics can also be used.The plain bearings can also be replaced by a roller bearing, andlikewise the roller bearings in FIGS. 1 to 4 can also be realized in theform of plain bearings.

FIG. 6 illustrates a variant of a flywheel which has a plurality ofinertial masses, and which differs from the embodiments described aboveprimarily as a result of the presence of an additional, ring-shapedinertial mass component 113. The inertial mass component 113 can berotationally driven around the axis of rotation 1 d by the inertial massbodies 57 d in the manner of a transmission or drive chain. The inertialmass component 113 surrounds the axis of rotation 1 d and is engagedwith a toothing 115, which toothing 115 is provided on the outsideperiphery of inertial mass component 113, in the toothing 65 d of eachindividual inertial mass body 57 d. The toothing 65 d can also beengaged with the mating toothing 67 d of the sheet metal structural part19 d. While the mating toothing 67 d surrounds the inertial mass bodies57 d in a ring fashion on the side which faces radially away from theaxis of rotation 1 d, the inertial mass component 113 is located on theside which is preferably radially closer to the axis of rotation 1 d. Inthe event of relative rotation of the two inertial mass systems 3 d, 7d, the inertial mass bodies 57 d which can rotate on journals 59 daround corresponding respective axes of rotation 63 d act as“intermediate gear wheels” which can drive the ring-shaped inertial masscomponent 113 in rotation.

In another possible embodiment of the present invention the inertialmass component 113 can have an outer periphery with toothing 115. Thetoothing 115 of the inertial mass component 113 can engage the toothing65 d of the inertial mass bodies 57 d. The toothing 65 d of the inertialmass bodies 57 d may also engage mating toothing 67 d on the sheet metalstructural part 19 d. The inertial mass component 113 is preferablylocated on the radial inside of the inertial mass bodies 57 d.

While in the embodiments illustrated in FIGS. 1 to 4 explained above,the journals are realized in the form of separate components which areinserted in sheet metal structural parts of the first inertial masssystem, the journals 59 d are stamped out of the sheet metal structuralpart 11 d. The inertial mass bodies 57 d are mounted by means of planbearing bushes 61 d on these journals 95 d.

The ring-shaped inertial mass component 113 is guided in a floatingmanner between axial and radially neighboring components, and is guidedradially in particular by the number of inertial mass bodies 57 d whichare offset from one another in the peripheral direction. In addition toor instead of the guidance by the toothings 65 d, the inertial masscomponent 113 can also be guided radially on an essentiallyaxially-extending peripheral wall 117 of a ring-shaped sheet metalsealing part 119, and which together with the sheet metal structuralpart 19 d forms a dynamic seal which can be placed under a slightapplication pressure, if necessary, and is also bolted, together withthe sheet metal structural part 11 d, to the crankshaft by means ofcrankshaft fastening bolts 121 which project through the fastening holes17 d of the sheet metal structural part 11 d.

As also illustrated in FIG. 6, the inertial mass bodies 57 d, axially toone side of their toothings 65 d, to increase their moment of inertia,have a radially projecting ring flange 69 d which extends radiallybeyond the toothing 115 of the inertial mass component 113. In thismanner, a very high moment of inertia can be achieved in a relativelysmall space.

In contrast to the embodiments described above, in which the annular webis formed by a Z-shaped bending of the sheet metal structural part 19 d,the annular web 73 d in FIG. 6 is created by stamping a step, whichreduces the cross section of the material. The flywheel 27 d is providedir the vicinity of the rivets with a number of ribs 125 (see FIG. 6a)which project radially, and which form cooling air channels 123 whichrun radially between the ribs 125 and the sheet metal structural part 19d, and which connect the area of the inside periphery of the flywheel 27d with the annular gap 81 d which leads radially outward.

In variants of the embodiment illustrated in FIG. 6, the inertial masscomponent 113 can also surround the inertial mass bodies 57 d on theradial outside, in which case, as in the embodiment illustrated in FIG.4, the mating toothing 67 d is located on the side facing the axis ofrotation 1 d. Here again, however, the inertial mass component islocated axially between the two sheet metal structural parts 11 d, 19 d.

One feature of the invention resides broadly in the torsional vibrationdamper, in particular for installation in the drive train of a motorvehicle, comprising three inertial mass systems 3, 7, 57, a first 3 anda second 7 inertial mass system are oriented so that they can rotatejointly and also relative to one another around a common first axis ofrotation 1, and are connected rotationally and elastically to oneanother by means of a spring system 9, and a third inertial mass system57 which is movable relative to the first 3 and the second 7 inertialmass systems and is rotationally connected by means of a transmissionsystem 65, 57 to the first 3 and/or second 7 inertial mass system,whereby one of the inertial mass systems, in particular the firstinertial mass system 3, is designed to be connected to the crankshaft ofan internal combustion engine, characterized by the fact that theinertial mass of the third inertial mass system is determinedessentially exclusively by inertial masses of a plurality of inertialmass bodies 57 which rotate around the first axis of rotation 1, wherebyeach inertial mass body can rotate or pivot around a second axis ofrotation 63 which is axially parallel to and offset from the first axisof rotation 1, and each inertial mass body 57 is driven or pivotedaround its second axis of rotation 63 by the transmission system 65, 67as a function of the relative rotational movement between the first 3and second 7 inertial mass systems.

Another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the inertial mass bodies57, 57 a, 57 b, at least on a portion of their periphery, are providedwith toothing 65, 65 a, 65 b which is concentric to the correspondingsecond axis of rotation 63, 63 a, 63 b and are mounted relative to thefirst inertial mass system 3, 3 a, 3 b in a stationary manner on thefirst inertial mass system, and that the second inertial mass system 7,7 a, 7 b comprises a mating toothing 67, 67 a, 67 b which is concentricto the first axis of rotation 1, 1 a, 1 b and is engaged with thetoothing 65, 65 a, 65 b.

Yet another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the mating toothing 67,67 a, 67 b is provided exclusively on the side of the inertial massbodies 57, 57 a which faces radially away from the first axis ofrotation 1, 1 a, or exclusively on the side of the inertial mass bodies57 b which faces radially toward the first axis of rotation 1 b.

Still another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the inertial mass bodies57, 57 a, 57 b are mounted on journals 59, 59 a, 59 b which arenon-detachably connected to the first inertial mass system 3, 3 a, 3 b.

A further feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that there is a fourthinertial mass system 113 which can rotate around the first axis ofrotation id relative to the first 3 d and the second 7 d inertial masssystems, which fourth inertial mass system 113 is in a rotational driveconnection via an additional transmission system 65 d, 115 with at leastone of the inertial mass bodies 57 d, and can be driven so that itrotates or pivots around the first axis of rotation 1 d as a function ofthe relative movement between the inertial mass bodies 57 d on one handand the first 3 d and the second 7 d inertial mass systems on the otherhand.

Another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that at least the oneinertial mass body 57 d and in particular each of the inertial massbodies 57 d are provided at least over a portion of the periphery withtoothing 65 d which is concentric to the corresponding second axis ofrotation 63 d and that the fourth inertial mass system comprises, aring-shaped inertial mass component 113 which can rotate relative to thefirst 3 d and the second 7 d inertial mass system around the first axisof rotation. To form an additional transmission system, the inertialmass component 113 can have a mating toothing 115 which is concentric tothe first axis of rotation 1 d and engages with the toothing 65 d.

Yet another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the toothing of at leastone inertial mass body 57 d is engaged on diametrically opposite sidesof the second axis of rotation 63 d with mating toothings 67 d, 115 ofthe transmission system and of the additional transmission system.

Still another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the mating toothing 115of the ring-shaped inertial mass component 113 is engaged in thetoothing 65 d of the inertial mass body 57 d on the side of eachinertial mass body 57 d next to the first axis of rotation 1 d.

A further feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the ring-shaped inertialmass component 113 is guided radially on an annular shoulder 117 whichis connected to one of the inertial mass systems, in particular thefirst inertial mass system 3 d, and/or on the toothings 65 d of aplurality of inertial mass bodies 57 d offset in the peripheraldirection around the first axis of rotation 1 d.

Another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the annular shoulder 117is provided on a ring-shaped sheet metal structural part 119, inparticular on a sheet metal structural part which is used to form adynamic seal and which is non-detachably fastened to the first inertialmass system 3 d.

Yet another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the inertial mass bodies57 d extend radially beyond the mating toothing 115 of the ring-shapedinertial mass component 113.

Still another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the inertial mass bodies57 c are realized in the form of rolling bodies, and are provided overat least a portion of the periphery with a toothing 65 c which isconcentric to the corresponding second axis of rotation 63 c, and thatthe first inertial mass system 3 c comprises a guide track 99 which isconcentric to the first axis of rotation 1 c for the inertial massbodies 57 c and the second inertial mass system 7 c comprises a matingtoothing 67 c which is concentric to the first axis of rotation 1 c andis engaged with the toothing 65 c of the inertial mass bodies 57 c,whereby the guide track 99 and the mating toothing 67 c guide theinertial mass bodies 57 c radially.

A further feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the mating toothing 67 cof the second inertial mass system 7 c is engaged on the side of theinertial mass bodies 57 c which faces radially away from the first axisof rotation 1 c with the toothing 65 c of the inertial mass bodies 57 c.

Another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the guide track is alsorealized in the form of a mating toothing 99 which can be engaged withthe toothing 65 c.

Yet another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the inertial mass bodies57, 57 a, 57 c, for the rotational drive connection to the first 3, 3 a,3 c or the second 7, 7 a, 7 c inertial mass system have, at least over aportion of their periphery, toothing 65, 65 a, 65 c which is concentricto the corresponding second axis of rotation 63, 63 a, 63 c and alsohave material areas 69, 69 a, 69 c which project radially outward and/oraxially beyond the toothing 65, 65 a, 65 c to increase the inertialmass.

Still another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the first 3 or thesecond 7 inertial mass system, but in particular the first inertial masssystem 3, has a first sheet metal structural part 11 with a first planarannular wall 13 which runs essentially radially in relation to the firstaxis of rotation, and an at least approximately ring-shaped chamber 41located in the radially outer area of the first sheet metal structuralpart 11 which surrounds the first axis of rotation 1 essentiallyconcentrically to contain at least one spring 51 of the spring system 9,which spring 51 is connected to the first sheet metal structural part11, that the other 7 of these two inertial mass systems 3, 7 has asecond sheet metal structural part 19 which is coupled in the chamber 41with the spring 51, which sheet metal structural part 19, with a secondplanar annular wall 71, is opposite and at some distance of the firstannular wall 13, which second annular wall 71 runs essentially radiallyin relation to the first axis of rotation 1, and that the inertial massbodies 57 are located axially between the radially running annular walls13, 71 of the sheet metal structural parts 11, 19, and the chamber 41surrounds all the inertial mass bodies 57 on the radial outside.

A further feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the chamber 41 isrealized at least radially outward in a sealed manner to hold a viscousmedium, and the first 13 and/or the second 71 annular wall, at least inan area radially next to the chamber 41, runs axially close to one axialend surface of the inertial mass bodies 57.

Another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the inertial mass bodies57, 57 a, 57 c, at least over a portion of their periphery, are providedwith toothing 65, 65 a, 65 c concentric to the corresponding second axisof rotation 63, 63 a, 63 c, and one of the sheet metal structural parts11, 11 a, 11 c, 19, 19 a, 19 c, in particular the second sheet metalstructural part 19, 19 a, 19 c is provided with a mating toothing 67, 67a, 67 c which is engaged with the toothing 65, 65 a, 65 c and isconcentric to the first axis of rotation 1, 1 a, 1 c, and that theannular wall 71, 71 a, 71 c of the sheet metal structural part 19, 19 a,19 c comprising the mating toothing 67, 67 a, 67 c makes a transition,forming a radially open annular pocket 79, 79 a, 79 c into an annulararea 47, 47 a, 47 c of the sheet metal structural part 19, 19 a, 19 cwhich contains the mating toothing 67, 67 a, 67 c.

Yet another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the ring area 47, 47 a,47 c is realized in the form of an annular disc provided with the matingtoothing 67, 67 a, 67 c, and is held, in particular by welding, on adisc part of the sheet metal structural part 19, 19 a, 19 c, which discpart forms the annular wall 71, 71 a, 71 c.

Still another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the second sheet metalstructural part 19, on the side of the second annular wall 71 whichfaces the first axis of rotation 1, forms an annular web 73 which leadsaxially away from the first sheet metal structural part 11, whichannular web 73 connects the second annular wall 71 with a hub area 21 ofthe second sheet metal part 19, which hub area acts as a pivot bearing,that the hub area 21 carries a ring-shaped flywheel 27 which is locatedat some axial distance from the second annular wall 71, and that a thirdannular wall 39 of the first sheet metal structural part 3 extendsradially, into the space which is axially between the second annularwall 71 and the flywheel 27 and forms the axial limit of the chamber 41toward the flywheel 27.

A further feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the third annular wall39 overlaps the second annular wall 71, at least in a portion of itsarea, with an essentially parallel surface.

Another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the second 71 b, 71 cand the third 39 b, 39 c annular wall, in the vicinity of the insideperiphery of the third annular wall 39 b, 39 c form an annular gap 95,95 c which becomes wider toward the radial inside.

Yet another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the annular gap 95 c isformed by an encircling bead 93 c of the third annular wall 39 c, andthe third annular wall 39 c, on the side of the bead 93 c closer to thefirst axis of rotation 1 c, runs toward the second sheet metalstructural part 19 c.

Still another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the third annular wall39 c, in an area between the bead 93 c and the first axis of rotation 1c, forms a dynamic seal 109 with the second sheet metal structural part19 c.

A further feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the third annular wall39 extends essentially to the annular web 73.

Another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the hub area 21 b, 21 cof the second sheet metal structural part 19 b, 19 c, radially betweenthe annular web 73 b, 73 c and the flywheel 27 b, 27 c has a pluralityof openings 97, 97 c which are offset from one another in the peripheraldirection, and that between the flywheel 27 b, 27 c and the thirdannular wall 39 b, 39 c, an annular gap 81 b, 81 c is formed which isopen toward the radial outside.

Yet another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the third annular wall39 b, 39 c extends with its inside periphery radially into the areabetween the annular web 73 b, 73 c and the openings 97, 97 c, and in thevicinity of its inside periphery is bent axially away from the secondannular wall 71 b, 71 c.

Still another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the annular web 73 b isrealized in the form of a sleeve or bushing which, on the side of theinertial mass bodies 57 b next to the first axis of rotation 1 b,overlaps axially with the toothing 65 b of the inertial mass bodies 57b, and carries the mating toothing 67 b.

A further feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the sleeve extends toclose up against the first sheet metal structural part 11 b, and inparticular forms a dynamic seal with the first sheet metal structuralpart 11 b.

Another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that a dynamic seal 109 isformed between the second sheet metal structural part 11 c and the thirdannular wall 39 b, in particular the radially inner edge of the thirdannular wall 39 b.

Yet another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that radially between thefirst axis of rotation 1 a-d and the inertial mass bodies 57 a-d, thereis a dynamic seal 87, 91, 87 c, 119 between the first 3 a-d and thesecond 7 a-d sheet metal structural part.

Still another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the dynamic sealcomprises a sheet metal sealing part 119, which is screwed to thecrankshaft, together with the first inertial mass system 3 d, by meansof the same screws 121.

A further feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the toothing 65; 65 a,65 c, 65 d of the inertial mass bodies 57, 57 a, 57 c, 57 d is closedaxially, at least on one side.

Another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the second sheet metalstructural part 19 and the third annular wall 39 are frictionallysupported on one another, at least in a partial area.

Yet another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the inertial mass bodies57 are mounted rotationally, and in particular cantilevered, by means ofjournals 59 on the first sheet metal structural part 11.

Still another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the journal 59 d areformed in one piece, in particular stamped, on the first sheet metalstructural part 11 d.

A further feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the inertial mass bodies57 d are provided over at least a portion of their periphery withtoothing 65 d which is concentric to the corresponding second axis ofrotation 63 d, in which teeth are engaged the mating toothing 67 d ofthe other 7 d of the two inertial mass systems 3 d, 7 d, which matingtoothing 67 d is concentric to the first axis of rotation 1 d, as wellas an additional mating toothing 115 of a ring-shaped inertial masscomponent 113 which can rotate relative to the first sheet metalstructural part 11 d around the first axis of rotation, on diametricallyopposite sides relative to the second axis of rotation 63 d.

Another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the ring-shaped inertialmass component 115 is engaged in the toothing 65 d of the inertial massbodies 57 d on the side of the inertial mass bodies 57 d radially nextto the first axis of rotation 1 d.

Yet another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the inertial mass bodies57 a, 57 c are located axially between annular walls 13 a, 13 c, 71 a,71 c which run essentially radially and the second 7 a, 7 c inertialmass system, and are held by at least one axially acting spring 85, 85c, in particular a plate spring, in a frictional connection with atleast one of these annular walls 13 a, 13 c, 71 a, 71 c.

Still another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the first 3 and thesecond 7 inertial mass systems have sheet metal structural parts 11, 19which axially surround the inertial mass bodies 57 between annular walls13, 71 which run essentially radially, and that the annular walls 13, 71make a transition toward the first axis of rotation 1 into hub areas 15,21, 23 in which the two inertial mass systems 3, 7 are mounted so thatthey can rotate radially relative to one another.

A further feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the sheet metalstructural parts 11, 19 have integral, coaxial bearing lugs 15, 23 whichare engaged with one another, by means of which they are mounted on oneanother.

Another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the bearing lugs 15, 23project axially toward on one another from the sheet metal structuralparts 11, 19.

Yet another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the bearing is realizedin the form of a plain bearing 5 c and comprises a bearing ring 111, inparticular one made of plastic.

Still another feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that the bearing ring 111 hasan L-shaped cross section, and guides the sheet metal structural parts11 c, 19 c both radially and axially in relation to one another.

A further feature of the invention resides broadly in the torsionalvibration damper characterized by the fact that one of the sheet metalstructural parts 11, 19, in particular the first sheet metal structuralpart 11, is provided with fastening means 17 for the attachment to thecrankshaft of the internal combustion engine, and with its bearing lug15, surrounds or encloses the bearing lug 23 of the other sheet metalstructural part 19 from the radial outside.

Another feature of the invention resides broadly in the two massflywheel, wherein said first inertial mass system comprises at least onehole to receive a bolt for connecting said first inertial mass system toa crankshaft of an internal combustion engine; said first inertial masssystem is configured to be connected to a crankshaft of a motor vehicle;said two mass flywheel further comprises a spring arrangement; saidspring arrangement is disposed in said chamber; said first inertial masssystem is operatively connected to said spring arrangement; said secondinertial mass system is operatively connected to said springarrangement; said spring arrangement comprises at least one coilcompression spring; said first structural portion comprises sheet metal;said second structural portion comprises sheet metal; said viscousmedium is at least partially disposed in said chamber; said viscousmedium comprises grease; each planet gear of said plurality of planetgears comprises: a first end surface; said first end surface is disposedsubstantially perpendicular to the common axis of rotation; said firstend surface is disposed adjacent to said first annular wall; a secondend surface; said second end surface is disposed substantiallyperpendicular to said common axis of rotation; said second end surfaceis disposed adjacent to said second annular wall; and at least one ofsaid first annular wall and said second annular wall is disposed aminimal distance from the corresponding one of said first end surfaceand said second end surface; said first inertial mass system comprises:a first wall portion; said first wall portion is connected to said firstannular wall; said first wall portion is substantially perpendicular tothe common axis of rotation; said first wall portion extends away fromsaid first annular wall in a substantially radial direction; a secondwall portion; said second wall portion is connected to said first wallportion; said second wall portion is substantially perpendicular to saidfirst wall portion; and said second wall portion extends in asubstantially axial direction from said first wall portion toward saidsecond inertial mass system; said third annular wall is attached to saidsecond wall portion; said first wall portion, said second wall portionand said third annular wall are disposed to together define at least aportion of said chamber; said set of teeth of said sun gear is disposeda fifth distance from the common axis of rotation; said fourth distanceis greater than said fifth distance; and said annular web is configuredto form a sleeve.

Examples of clutches, and components associated therewith which may beutilized in accordance with embodiments of the present invention, may befound in the following U.S. Pat. Nos. 5,000,304; 4,941,558; 4,854,438;4,741,423; and 4,715,485.

Examples of torsional vibration dampers, and components associatedtherewith, which may be used in accordance with embodiments of thepresent invention, may be found in the following U.S. Pat. Nos.5,016,744; 4,433,771; 4,684,007; 4,697,682; 4,890,712; and 4,651,857.

U.S. Pat. No. 5,551,928, having the inventor Jörg Sudau entitled“Torsional Vibration Damper with Planetary Gearset”, is herebyincorporated by reference as if set forth in its entirety herein.

The following U.S. Patents are hereby incorporated by reference as ifset forth in their entirety herein: U.S. Pat. No. 5,634,866, whichissued on Jun. 3, 1997 to inventor Sudau; U.S. Pat. No. 5,836,216, whichissued on Nov. 17, 1998 to inventors Sudau, et al.; and U.S. Pat. No.5,878,856, which issued on Mar. 9, 1999 to inventors Sudau, et al.

The drawings in their entirety, including all dimensions, proportionsand/or shapes in at least one embodiment of the invention, are accurateand to scale and are hereby included by reference into thisspecification.

All, or substantially all, of the components and methods of the variousembodiments may be used with at least one embodiment or all of theembodiments described herein.

All of the patents, patent applications and publications recited herein,and in the Declaration, are hereby incorporated by reference as if setforth in their entirety herein.

The corresponding foreign patent publication applications, namely,Federal Republic of Germany Patent Application No. 196 09 041.5, filedon Mar. 8, 1996, having inventor Jörg Sudau, and DE-OS 196 09 041.5 andDE-PS 196 09 041.5, as well as their published equivalents, and otherequivalents or corresponding applications, if any, in correspondingcases in the Federal Republic of Germany and elsewhere, and thereferences cited in any of the documents cited herein, are herebyincorporated by reference as if set forth in their entirety herein.

Although only a few exemplary embodiments of this invention have beendescribed in detail above, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe following claims. In the claims, means-plus-function clause areintended to cover the structures described herein as performing therecited function and not only structural equivalents but also equivalentstructures.

The invention as described hereinabove in the context of the preferredembodiments is not to be taken as limited to all of the provided detailsthereof, since modifications and variations thereof may be made withoutdeparting from the spirit and scope of the invention.

What is claimed is:
 1. A two mass flywheel for use in a drive train of a motor vehicle, said two mass flywheel comprising: a first inertial mass system; a second inertial mass system; one of said first inertial mass system and said second inertial mass system being configured to be connected to a crankshaft of an internal combustion engine and the other of said first inertial mass system and said second inertial mass system being configured to be connected to a transmission system; said first inertial mass system comprising at least one planet gear; said second inertial mass system comprising a sun gear; said sun gear being configured and disposed to engage said at least one planet gear to impart rotation from and between said at least one planet gear and said sun gear; said at least one planet gear being configured and disposed to solely engage said sun gear; said at least one planet gear comprises a plurality of planet gears; said first inertial mass system, said second inertial mass system, and said sun gear have a substantially common axis of rotation; each planet gear of said plurality of planet gears has a corresponding axis of rotation; each planet gear of said plurality of planet gears comprises a cylindrical edge; said cylindrical edge of each planet gear of said plurality of planet gears is disposed concentric to the corresponding axis of rotation of each planet gear of said plurality of planet gears; each planet gear of said plurality of planet gears comprises a set of teeth; said set of teeth is disposed on at least a portion of said cylindrical edge of each planet gear of said plurality of planet gears; said sun gear comprises a cylindrical edge; said cylindrical edge of said sun gear is disposed concentric to the common axis of rotation; said sun gear comprises a set of teeth; said set of teeth of said sun gear is disposed on at least a portion of said cylindrical edge of said sun gear; said set of teeth of said sun gear is configured and disposed to engage with said set of teeth of each planet gear of said plurality of planet gears; a first structural portion; a second structural portion; a first annular wall; a second annular wall; said first inertial mass system comprises said first structural portion; said first structural portion is disposed substantially concentric to the common axis of rotation; said first structural portion comprises said first annular wall; said first annular wall is disposed substantially perpendicular to the common axis of rotation; said first annular wall is substantially planar; said second inertial mass system comprises said second structural portion; said second structural portion is disposed substantially concentric to the common axis of rotation; said second structural portion comprises said second annular wall; said second annular wall is disposed substantially perpendicular to the common axis of rotation; said second annular wall is substantially planar; said second annular wall is disposed an axial distance from said first annular wall; and at least a portion of each planet gear of said plurality of planet gears is disposed between said first annular wall and said second annular wall.
 2. The two mass flywheel according to claim 1, wherein: the common axis of rotation defines an axial direction substantially parallel to the common axis of rotation; said two mass flywheel further comprises: a first hub area; a second hub area; a first bearing lug; a second bearing lug; said first structural portion comprises said first hub area; said first hub area comprises said first bearing lug; said first bearing lug extends in the axial direction from said first structural portion toward said second structural portion; said second structural portion comprises an annular web; said annular web extends from said second annular wall substantially in the axial direction and substantially concentric to the common axis of rotation; said sun gear is disposed on or about said annular web; said second structural portion comprises said second hub area; said second hub area is connected to said annular web; said second hub area comprises said second bearing lug; said second bearing lug extends in the axial direction from said second structural portion toward said first structural portion; said first bearing lug is disposed to cover at least a portion of said second bearing lug; said first bearing lug is disposed a first distance from said common axis of rotation; said second bearing lug is disposed a second distance from said common axis of rotation; and said first distance is greater than said second distance.
 3. The two mass flywheel according to claim 2, further comprising: a bearing arrangement to operatively connect said first bearing lug to said second bearing lug; said bearing arrangement being disposed between said first bearing lug and said second bearing lug; a flywheel portion; said flywheel portion being attached to said second hub area; said flywheel portion being configured to extend away from said second hub area in a substantially radial direction; said flywheel portion being disposed an axial distance from said second annular wall; a chamber; said chamber being disposed substantially concentric to the common axis of rotation; said chamber being configured to contain a viscous medium; said chamber being disposed a third distance from the common axis of rotation; the axis of rotation of each planet gear of said plurality of planet gears being disposed a fourth distance from the common axis of rotation; said third distance being greater than said fourth distance; a third annular wall; said first inertial mass system comprising said third annular wall; said third annular wall being disposed between said flywheel portion and said second annular wall; said third annular wall being substantially perpendicular to the common axis of rotation; said third annular wall being configured to extend substantially to said annular web; and said third annular wall being disposed to cover at least a portion of said second annular wall.
 4. The two mass flywheel according to claim 3, wherein: said first inertial mass system comprises at least one hole to receive a bolt for connecting said first inertial mass system to a crankshaft of an internal combustion engine; said first inertial mass system is configured to be connected to a crankshaft of a motor vehicle; said two mass flywheel further comprises a spring arrangement; said spring arrangement is disposed in said chamber; said first inertial mass system is operatively connected to said spring arrangement; said second inertial mass system is operatively connected to said spring arrangement; said spring arrangement comprises at least one coil compression spring; said first structural portion comprises sheet metal; said second structural portion comprises sheet metal; said viscous medium is at least partially disposed in said chamber; said viscous medium comprises grease; each planet gear of said plurality of planet gears comprises: a first end surface; said first end surface is disposed substantially perpendicular to the common axis of rotation; said first end surface is disposed adjacent to said first annular wall; a second end surface; said second end surface is disposed substantially perpendicular to said common axis of rotation; said second end surface is disposed adjacent to said second annular wall; and at least one of said first annular wall and said second annular wall is disposed a minimal distance from the corresponding one of said first end surface and said second end surface; said first inertial mass system comprises: a first wall portion; said first wall portion is connected to said first annular wall; said first wall portion is substantially perpendicular to the common axis of rotation; said first wall portion extends away from said first annular wall in a substantially radial direction; a second wall portion; said second wall portion is connected to said first wall portion; said second wall portion is substantially perpendicular to said first wall portion; and said second wall portion extends in a substantially axial direction from said first wall portion toward said second inertial mass system; said third annular wall is attached to said second wall portion; said first wall portion, said second wall portion and said third annular wall are disposed to together define at least a portion of said chamber; said set of teeth of said sun gear is disposed a fifth distance from the common axis of rotation; said fourth distance is greater than said fifth distance; and said annular web is configured to form a sleeve.
 5. The two mass flywheel according to claim 4, further comprising: a first annular gap; said first annular gap being disposed between said second annular wall and said third annular wall; said third annular wall comprising an end portion; said end portion being disposed opposite said second wall portion; said end portion extending in a substantially axial direction away from said second annular wall; a second annular gap; said second annular gap being disposed between said third annular wall and said flywheel portion; said second hub area comprising at least one opening; said at least one opening being disposed between said annular web and said flywheel portion; said at least one opening being disposed adjacent to said second annular gap; said at least one opening being configured to permit passage of air into said second hub area; said end portion being configured to deflect air entering said at least one opening into said second annular gap; a sealing arrangement; said sealing arrangement being disposed between said first structural portion and said second structural portion; said sealing arrangement being disposed between said plurality of planet gears and said first bearing lug; said annular web being at least a portion of said sealing arrangement; said annular web being configured to form a dynamic seal between said first structural portion and said second structural portion; said first inertial mass system comprises a mounting arrangement; said mounting arrangement being configured to mount each planet gear of said plurality of planet gears stationary with respect to said first inertial mass system; said mounting arrangement comprising: a plurality of journals corresponding to said plurality of planet gears; a plurality of bearings corresponding to said plurality of planet gears; each bearing of said plurality of bearings being rotatably mounted on a corresponding one of said plurality of journals; and each planet gear of said plurality of planet gears being disposed on a corresponding one of said plurality of bearings; said first inertial mass system comprising a third wall portion; said third wall portion extending from said second wall portion in a substantially axial direction; and said third wall portion axially extending beyond said second annular wall.
 6. A two mass flywheel for use in a drive train of a motor vehicle, said two mass flywheel comprising: a first inertial mass system; a second inertial mass system; one of said first inertial mass system and said second inertial mass system being configured to be connected to a crankshaft of an internal combustion engine and the other of said first inertial mass system and said second inertial mass system being configured to be connected to a transmission system; said first inertial mass system comprising at least one planet gear; said second inertial mass system comprising a sun gear; said sun gear being configured and disposed to engage said at least one planet gear to impart rotation and substantially all of the torque from and between said at least one planet gear and said sun gear; said at least one planet gear comprises a plurality of planet gears; said first inertial mass system, said second inertial mass system, and said sun gear have a substantially common axis of rotation; each planet gear of said plurality of planet gears has a corresponding axis of rotation; each planet gear of said plurality of planet gears comprises a cylindrical edge; said cylindrical edge of each planet gear of said plurality of planet gears is disposed concentric to the corresponding axis of rotation of each planet gear of said plurality of planet gears; each planet gear of said plurality of planet gears comprises a set of teeth; said set of teeth is disposed on at least a portion of said cylindrical edge of each planet gear of said plurality of planet gears; said sun gear comprises a cylindrical edge; said cylindrical edge of said sun gear is disposed concentric to the common axis of rotation; said sun gear comprises a set of teeth; said set of teeth of said sun gear is disposed on at least a portion of said cylindrical edge of said sun gear; said set of teeth of said sun gear is configured and disposed to engage with said set of teeth of each planet gear of said plurality of planet gears; a first structural portion; a second structural portion; a first annular wall; a second annular wall; said first inertial mass system comprises said first structural portion; said first structural portion is disposed substantially concentric to the common axis of rotation; said first structural portion comprises said first annular wall; said first annular wall is disposed substantially perpendicular to the common axis of rotation; said first annular wall is substantially planar; said second inertial mass system comprises said second structural portion; said second structural portion is disposed substantially concentric to the common axis of rotation; said second structural portion comprises said second annular wall; said second annular wall is disposed substantially perpendicular to the common axis of rotation; said second annular wall is substantially planar; said second annular wall is disposed an axial distance from said first annular wall; and at least a portion of each planet gear of said plurality of planet gears is disposed between said first annular wall and said second annular wall.
 7. The two mass flywheel according to claim 6, wherein: the common axis of rotation defines an axial direction substantially parallel to the common axis of rotation; said two mass flywheel further comprises: a first hub area; a second hub area; a first bearing lug; a second bearing lug; said first structural portion comprises said first hub area; said first hub area comprises said first bearing lug; said first bearing lug extends in the axial direction from said first structural portion toward said second structural portion; said second structural portion comprises an annular web; said annular web extends from said second annular wall substantially in the axial direction and substantially concentric to the common axis of rotation; said sun gear is disposed on or about said annular web; said second structural portion comprises said second hub area; said second hub area is connected to said annular web; said second hub area comprises said second bearing lug; said second bearing lug extends in the axial direction from said second structural portion toward said first structural portion; said first bearing lug is disposed to cover at least a portion of said second bearing lug; said first bearing lug is disposed a first distance from said common axis of rotation; said second bearing lug is disposed a second distance from said common axis of rotation; said first distance is greater than said second distance; said two mass flywheel further comprises: a bearing arrangement to operatively connect said first bearing lug to said second bearing lug; said bearing arrangement is disposed between said first bearing lug and said second bearing lug; a flywheel portion; said flywheel portion is attached to said second hub area; said flywheel portion is configured to extend away from said second hub area in a substantially radial direction; said flywheel portion is disposed an axial distance from said second annular wall; a chamber; said chamber is disposed substantially concentric to the common axis of rotation; said chamber is configured to contain a viscous medium; said chamber is disposed a third distance from the common axis of rotation; the axis of rotation of each planet gear of said plurality of planet gears is disposed a fourth distance from the common axis of rotation; said third distance is greater than said fourth distance; a third annular wall; said first inertial mass system comprises said third annular wall; said third annular wall is disposed between said flywheel portion and said second annular wall; said third annular wall is substantially perpendicular to the common axis of rotation; said third annular wall is configured to extend substantially to said annular web; and said third annular wall is disposed to cover at least a portion of said second annular wall.
 8. The two mass flywheel according to claim 7, wherein: said first inertial mass system comprises at least one hole to receive a bolt for connecting said first inertial mass system to a crankshaft of an internal combustion engine; said first inertial mass system is configured to be connected to a crankshaft of a motor vehicle; said two mass flywheel further comprises a spring arrangement; said spring arrangement is disposed in said chamber; said first inertial mass system is operatively connected to said spring arrangement; said second inertial mass system is operatively connected to said spring arrangement; said spring arrangement comprises at least one coil compression spring; said first structural portion comprises sheet metal; said second structural portion comprises sheet metal; said viscous medium is at least partially disposed in said chamber; said viscous medium comprises grease; each planet gear of said plurality of planet gears comprises: a first end surface; said first end surface is disposed substantially perpendicular to the common axis of rotation; said first end surface is disposed adjacent to said first annular wall; a second end surface; said second end surface is disposed substantially perpendicular to said common axis of rotation; said second end surface is disposed adjacent to said second annular wall; and at least one of said first annular wall and said second annular wall is disposed a minimal distance from the corresponding one of said first end surface and said second end surface; said first inertial mass system comprises: a first wall portion; said first wall portion is connected to said first annular wall; said first wall portion is substantially perpendicular to the common axis of rotation; said first wall portion extends away from said first annular wall in a substantially radial direction; a second wall portion; said second wall portion is connected to said first wall portion; said second wall portion is substantially perpendicular to said first wall portion; and said second wall portion extends in a substantially axial direction from said first wall portion toward said second inertial mass system; said third annular wall is attached to said second wall portion; said first wall portion, said second wall portion and said third annular wall are disposed to together define at least a portion of said chamber; said set of teeth of said sun gear is disposed a fifth distance from the common axis of rotation; said fourth distance is greater than said fifth distance; said annular web is configured to form a sleeve; said two mass flywheel further comprises: a first annular gap; said first annular gap is disposed between said second annular wall and said third annular wall; said third annular wall comprises an end portion; said end portion is disposed opposite said second wall portion; said end portion extends in a substantially axial direction away from said second annular wall; a second annular gap; said second annular gap is disposed between said third annular wall and said flywheel portion; said second hub area comprises at least one opening; said at least one opening is disposed between said annular web and said flywheel portion; said at least one opening is disposed adjacent to said second annular gap; said at least one opening is configured to permit passage of air into said second hub area; said end portion is configured to deflect air entering said at least one opening into said second annular gap; a sealing arrangement; said sealing arrangement is disposed between said first structural portion and said second structural portion; said sealing arrangement is disposed between said plurality of planet gears and said first bearing lug; said annular web is at least a portion of said sealing arrangement; said annular web is configured to form a dynamic seal between said first structural portion and said second structural portion; said first inertial mass system comprises a mounting arrangement; said mounting arrangement is configured to mount each planet gear of said plurality of planet gears stationary with respect to said first inertial mass system; said mounting arrangement comprises: a plurality of journals corresponding to said plurality of planet gears; a plurality of bearings corresponding to said plurality of planet gears; each bearing of said plurality of bearings is rotatably mounted on a corresponding one of said plurality of journals; and each planet gear of said plurality of planet gears is disposed on a corresponding one of said plurality of bearings; said first inertial mass system comprises a third wall portion; said third wall portion extends from said second wall portion in a substantially axial direction; and said third wall portion axially extends beyond said second annular wall.
 9. A two mass flywheel for use in a drive train of a motor vehicle, said two-mass flywheel comprising: a first inertial mass system; a second inertial mass system; one of said first inertial mass system and said second inertial mass system being configured to be connected to a crankshaft of an internal combustion engine and the other of said first inertial mass system and said second inertial mass system being configured to be connected to a transmission system; said first inertial mass system comprising a sun gear; said second inertial mass system comprising at least one planet gear; said sun gear being configured and disposed to engage said at least one planet gear to impart rotation and substantially all of the torque from and between said first inertial mass system and said second inertial mass system; said at least one planet gear comprises a plurality of planet gears; said first inertial mass system, said second inertial mass system, and said sun gear have a substantially common axis of rotation; each planet gear of said plurality of planet gears has a corresponding axis of rotation; each planet gear of said plurality of planet gears comprises a cylindrical edge; said cylindrical edge of each planet gear of said plurality of planet gears is disposed concentric to the corresponding axis of rotation of each planet gear of said plurality of planet gears; each planet gear of said plurality of planet gears comprises a set of teeth; said set of teeth is disposed on at least a portion of said cylindrical edge of each planet gear of said plurality of planet gears; said sun gear comprises a cylindrical edge; said cylindrical edge of said sun gear is disposed concentric to the common axis of rotation; said sun gear comprises a set of teeth; said set of teeth of said sun gear is disposed on at least a portion of said cylindrical edge of said sun gear; said set of teeth of said sun gear is configured and disposed to engage with said set of teeth of each planet gear of said plurality of planet gears a first structural portion; a second structural portion; a first annular wall; a second annular wall; said first inertial mass system comprises said first structural portion; said first structural portion is disposed substantially concentric to the common axis of rotation; said first structural portion comprises said first annular wall; said first annular wall is disposed substantially perpendicular to the common axis of rotation; said first annular wall is substantially planar; said second inertial mass system comprises said second structural portion; said second structural portion is disposed substantially concentric to the common axis of rotation; said second structural portion comprises said second annular wall; said second annular wall is disposed substantially perpendicular to the common axis of rotation; said second annular wall is substantially planar; said second annular wall is disposed an axial distance from said first annular wall; and at least a portion of each planet gear of said plurality of planet gears is disposed between said first annular wall and said second annular wall.
 10. The two mass flywheel according to claim 9, wherein: the common axis of rotation defines an axial direction substantially parallel to the common axis of rotation; said two mass flywheel further comprises: a first hub area; a second hub area; a first bearing lug; a second bearing lug; said first structural portion comprises said first hub area; said first hub area comprises said first bearing lug; said first bearing lug extends in the axial direction from said first structural portion toward said second structural portion; said second structural portion comprises an annular web; said annular web extends from said second annular wall substantially in the axial direction and substantially concentric to the common axis of rotation; said sun gear is disposed on or about said annular web; said second structural portion comprises said second hub area; said second hub area is connected to said annular web; said second hub area comprises said second bearing lug; said second bearing lug extends in the axial direction from said second structural portion toward said first structural portion; said first bearing lug is disposed to cover at least a portion of said second bearing lug; said first bearing lug is disposed a first distance from said common axis of rotation; said second bearing lug is disposed a second distance from said common axis of rotation; said first distance is greater than said second distance; said two mass flywheel further comprises: a bearing arrangement to operatively connect said first bearing lug to said second bearing lug; said bearing arrangement is disposed between said first bearing lug and said second bearing lug; a flywheel portion; said flywheel portion is attached to said second hub area; said flywheel portion is configured to extend away from said second hub area in a substantially radial direction; said flywheel portion is disposed an axial distance from said second annular wall; a chamber; said chamber is disposed substantially concentric to the common axis of rotation; said chamber is configured to contain a viscous medium; said chamber is disposed a third distance from the common axis of rotation; the axis of rotation of each planet gear of said plurality of planet gears is disposed a fourth distance from the common axis of rotation; said third distance is greater than said fourth distance; a third annular wall; said first inertial mass system comprises said third annular wall; said third annular wall is disposed between said flywheel portion and said second annular wall; said third annular wall is substantially perpendicular to the common axis of rotation; said third annular wall is configured to extend substantially to said annular web; and said third annular wall is disposed to cover at least a portion of said second annular wall.
 11. The two mass flywheel according to claim 10, wherein: said first inertial mass system comprises at least one hole to receive a bolt for connecting said first inertial mass system to a crankshaft of an internal combustion engine; said first inertial mass system to be connected to a crankshaft of a motor vehicle; said two mass flywheel further comprises a spring arrangement; said spring arrangement is disposed in said chamber; said first inertial mass system is operatively connected to said spring arrangement; said second inertial mass system is operatively connected to said spring arrangement; said spring arrangement comprises at least one coil compression spring; said first structural portion comprises sheet metal; said second structural portion comprises sheet metal; said viscous medium is at least partially disposed in said chamber; said viscous medium comprises grease; each planet gear of said plurality of planet gears comprises: a first end surface; said first end surface is disposed substantially perpendicular to the common axis of rotation; said first end surface is disposed adjacent to said first annular wall; a second end surface; said second end surface is disposed substantially perpendicular to said common axis of rotation; said second end surface is disposed adjacent to said second annular wall; and at least one of said first annular wall and said second annular wall is disposed a minimal distance from the corresponding one of said first end surface and said second end surface; said first inertial mass system comprises: a first wall portion; said first wall portion is connected to said first annular wall; said first wall portion is substantially perpendicular to the common axis of rotation; said first wall portion extends away from said first annular wall in a substantially radial direction; a second wall portion; said second wall portion is connected to said first wall portion; said second wall portion is substantially perpendicular to said first wall portion; and said second wall portion extends in a substantially axial direction from said first wall portion toward said second inertial mass system; said third annular wall is attached to said second wall portion; said first wall portion, said second wall portion and said third annular wall are disposed to together define at least a portion of said chamber; said set of teeth of said sun gear is disposed a fifth distance from the common axis of rotation; said fourth distance is greater than said fifth distance; said annular web is configured to form a sleeve; said two mass flywheel further comprises: a first annular gap; said first annular gap is disposed between said second annular wall and said third annular wall; said third annular wall comprises an end portion; said end portion is disposed opposite said second wall portion; said end portion extends in a substantially axial direction away from said second annular wall; a second annular gap; said second annular gap is disposed between said third annular wall and said flywheel portion; said second hub area comprises at least one opening; said at least one opening is disposed between said annular web and said flywheel portion; said at least one opening is disposed adjacent to said second annular gap; said at least one opening is configured to permit passage of air into said second hub area; said end portion is configured to deflect air entering said at least one opening into said second annular gap; a sealing arrangement; said sealing arrangement is disposed between said first structural portion and said second structural portion; said sealing arrangement is disposed between said plurality of planet gears and said first bearing lug; said annular web is at least a portion of said sealing arrangement; said annular web is configured to form a dynamic seal between said first structural portion and said second structural portion; said first inertial mass system comprises a mounting arrangement; said mounting arrangement is configured to mount each planet gear of said plurality of planet gears stationary with respect to said first inertial mass system; said mounting arrangement comprises: a plurality of journals corresponding to said plurality of planet gears; a plurality of bearings corresponding to said plurality of planet gears; each bearing of said plurality of bearings is rotatably mounted on a corresponding one of said plurality of journals; and each planet gear of said plurality of planet gears is disposed on a corresponding one of said plurality of bearings; said first inertial mass system comprises a third wall portion; said third wall portion extends from said second wall portion in a substantially axial direction; and said third wall portion axially extends beyond said second annular wall. 